Robots which are used to move and manipulate parts are typically comprised of a robotic arm having a gripper at the end thereof. The robotic arm is typically moved to position the gripper around the object to be grasped, and the gripper is then activated to grasp the object and hold it during movement of the robotic arm. Typically, such grippers are pneumatic. The gripper will typically have a full open position and will close with a constant amount of force upon the application of air pressure. Such pneumatic systems are usually limited in the amount of travel of the gripper fingers, with one inch being average. The gripper would close until the two fingers touch each other except for the intermediate contact with the object to be moved.
In a gripper previously sold by applicant, the gripper has a stationary finger and a moveable finger. The movable finger is controlled by a DC motor to position the finger as desired. An encoder on the shaft of the DC motor provides a feedback signal to a servo system which controls power to the DC motor. The system includes a serial port for providing assembly level commands to the servo system. The commands can be provided to the servo system of the gripper by the computer system controlling the robotic arm. The servo system output is coupled to the DC motor power supply through a linear analog amplifier. The motor is coupled to control the movable finger through a rack and pinion in one model or a ball screw and rack in another model.